Crazy Algorithms

9 Algorithms That Are Driving The World Crazy

1. Search Engine Indexing:

Finding needles in the world’s biggest haystack. Search for something on the web and you’re ‘indexing’ billions of documents and images. Not a trivial task and it needs smart algorithms to do it at all, never mind in a tiny, tiny fraction of a second.

2. PageRank:

The technology that made Google one of the biggest companies in the world. Google has moved on, or at least greatly refined the algorithm(s) mentioned here. Nevertheless, the multiple algorithms that rank results when you search are very smart.

3. Public Key Cryptography:

Sending secrets on a postcard, is a description of how encryption works and keeps your credit card details safe when buying stuff. Amazon, Ebay, PayPal, credit cards and the entire world of online retail would not exist without this algorithm.

4. Error Correcting Codes:

Mistakes that fix themselves, so that sound, pictures and videos can be saved, stored and retrieved without loss, even from a CD or DVD but especially across networks, where these clever algorithms maintain quality.

5. Pattern Recognition:

Learning from Experience on postcode readers, faces, license plates, in translation, speech recognition – pattern matching plucks out meaning from data. Mobile devices especially need to use these algorithms when you type on virtual keyboards or use handwriting software.

6. Data Compression:

Something for nothing when we zip files, compress for transmission, decompress for use. Lossless and lossy compression, and decompression, magically squeeze big files into little files for transfer.

7. Databases:

The quest for consistency describes how databases work. Again, the advent of big data means that the balance, in some contexts, has swung away from algorithms, towards the power of massive data sets. Nevertheless, when you use a database you use some clever algorithms.

8. Digital Signatures:

Who really wrote this software? Some very smart algorithms are used to create signatures for individual users.

9. What is computable?

Or more accurately what can’t be computed. Things don’t crash as often as they used to because algorithms catch the problems. However, some things, even using proof by contradiction don’t help and software has its limits. There are undecidable problems that computers can never solve.
This last of the nine, is a deliberate counterpoint, but it reads like an anomaly or personal enthusiasm, rather than a natural ninth algorithm. There’s a certainty about his abstract logic that is unwarranted, as we have quantum computing and philosophical arguments that allow us to question these certainties. It would have been much better to have written a chapter that shows the weaknesses of the algorithmic approach, such as our mistaken reliance on them in financial predictions, creating illusory certainties, the production of false positives and so on.